Citation style for this article: Vasconcelos P, Unit for Preparedness and Response. Flooding in Europe: a brief review of the health risks. Euro Surveill. 2006;11(16):pii=2947. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=2947
Date of submission:

In the light of current flooding events in Bulgaria, Serbia and Romania
[1], staff at the European Centre for Disease Prevention and Control (ECDC)
have undertaken some preliminary review of the adverse health effects of
such natural disasters.

Flood events are the most frequently occurring natural disasters worldwide,
and may increase in the future as a result of climate change [2]. Adverse
effects on human health include [3,4,5]:

• trauma deaths, mainly by drowning;
• injuries;
• enteric infections due to increased faeco-oral cycling from disruption
of sewage disposal and safe drinking water infrastructure;
• mental health such as post-traumatic stress disorder;
• vectorborne disease, such as malaria, dengue and dengue hemorrhagic fever,
yellow fever, and West Nile fever;
• rodent-borne disease, such as leptospirosis;
• poisoning caused by toxic substances;
• snake bites as snakes tend to seek shelter in households to escape from
flooding;
• other negative health outcomes, such as disruption of healthcare services
and population displacement.

A limited number of short term epidemiological studies have been undertaken
to assess the health impacts of flooding, but there is a deficiency in studies
of long term health and econoimc impacts. Population resilience is likely
to vary widely depending upon the economic and organizational resources
available.

Limited data on flood events shows that the greatest burden of mortality
is from drowning, heart attacks, hypothermia, trauma and vehicle related
accidents [4,5]. The speed of onset of floodwaters is a factor determining
the number of immediate flood-related deaths.
Flood-related injuries, such as contusions, cuts, sprains have been reported
in several studies [5,6], as well as burns, electrocutions, snake bites
and wound infections. After the tsunami of December 2004, 106 cases of tetanus
and 20 deaths were reported in Indonesia (case-fatality ratio 18.9%) [7].
However, the number of serious injuries observed after violent flooding
events generally turns out to be much lower than initial estimates predict.

Several studies in developed countries have reported increases in mental
health problems such as anxiety, depression, sleeplessness, and post-traumatic
stress disorder among flood victims [6]. A recent survey of flooded individuals
and a reference group of non-flooded individuals from the same area of residence
in the United Kingdom [8] found a fourfold increase in psychological distress
among adults whose homes were flooded compared with those whose homes were
not (RR=4.1, 95% CI: 2.6,6.4). The risk estimates for physical illness in
adults declined after adjustment for psychological distress, while psychological
distress remained strongly associated with flooding after adjustment for
physical illnesses. Other previous studies reported behaviour change in
children as increased bedwetting and aggression [9].

There is some evidence that diarrhoea disease increases after flooding,
particularly in developing countries, but also in Europe [6]. A recent UK
study reported an increase in self-reported gastroentereritis associated
with flooding and with increasing risk the greater the depth of household
flooding (RR 1.7 [0.9,3.0] p for trend by flood depth = 0.04) and an increase
in earache (RR 2.2 [1,1,4.1]) [7]. The large displacement of population
that occurs after flooding, and poor sheltering conditions and crowding
may also contribute to increase the risk of diarrhoeal and respiratory infections.Other
studies refer to evidence of flood-associated outbreaks of leptospirosis
in a wide range of countries, including Portugal (1969), the Russian Federation
(1997), and the Czech Republic (2003) [3,6,10]. Transmission is believed
to be promoted by skin and mucous membrane contact with water, damp soil,
vegetation or mud contaminated with rodent urine. Prompt recognition of
the disease and early treatment of cases is essential to minimise the impact
of the outbreak.

Floods may lead indirectly to an increase in vectorborne diseases through
the expansion in the number and range of vector habitats. Standing water
caused by heavy rainfall or overflow of rivers can act as breeding sites
for mosquitoes, and therefore enhance the potential for exposure of the
disaster-affected population and emergency workers to infections such as
dengue, malaria and West Nile fever. Flooding may initially flush out mosquito
breeding, but this will return when the waters recede. Malaria epidemics
in the wake of flooding are a well-known phenomenon in malaria-endemic areas
worldwide. West Nile fever has emerged in Europe after heavy rains and flooding,
with outbreaks in Romania in 1996-97, in the Czech Republic in 1997 and
Italy in 1998 [3]. There is also an increased risk of infection of diseases
contracted through direct contact with polluted waters, such as wound infections,
dermatitis, conjunctivitis, and ear, nose and throat infections.

The effects in developed regions, such as Europe, may be different to those
in developing regions. The World Health Organization Regional Office for
Europe has been developing several programmes related to assessing the health
effects of climate changes, including flooding, such as the project Climate
Change and Adaptation Strategies for Human Health (cCASHh) [11] that covers
aspects of impact and adaptation assessment for possible climate-related
health outcomes in Europe. The recent Rapid Health Assessment of Flooding
in Bulgaria [12], reported in 2005, covers the main public health issues
that should be considered during and after a flood and is one of the most
consistent documents on assessing the current situation and providing recommendations
for local response to flooding.

World Health Organization. Regional Office for Europe Europe. Disaster
Preparedness and Response Programme. Division of Country Support, Country
Policy, System and Services. Rapid health assessment of flooding in Bulgaria.
Final report. Copenhagen: 2005 (http://www.euro.who.int/document/EHA/RA_Bulrep.pdf)

Disclaimer: The opinions expressed by authors contributing to Eurosurveillance do not necessarily reflect the opinions of the European Centre for Disease Prevention and Control (ECDC) or the editorial team or the institutions with which the authors are affiliated. Neither ECDC nor any person acting on behalf of ECDC is responsible for the use that might be made of the information in this journal. The information provided on the Eurosurveillance site is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her physician. Our website does not host any form of commercial advertisement. Except where otherwise stated, all manuscripts published after 1 January 2016 will be published under the Creative Commons Attribution (CC BY) licence. You are free to share and adapt the material, but you must give appropriate credit, provide a link to the licence, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.